Concerning a communication method that uses electromagnetic waves, there has been proposed a wireless reception method structured in a manner that a sheet-shaped medium is used as a communication medium, a power feeding device for wireless power feeding is disposed in a nonconductive state in the sheet-shaped medium, and a reception side of the electromagnetic waves is also arranged in a nonconductive state in the sheet-shaped medium. Hereinafter, this communication method is referred to as surface communication. The sheet-shaped medium is configured to propagate the electromagnetic waves through a narrow area sandwiched by a pair of conductors located to face each other (e.g., refer to Patent Literature 1). Nonpatent Literature 1 discusses a principle of power communication through the sheet-shaped medium.
Nonpatent Literature 1 proposes, for the surface communication, a method to enable communication between two points on a two-dimensional sheet. Generally, it is preferred that power transport efficiency, namely, communication performance, between a power transmission unit and the reception unit, not be dependent on the position of the power transmission unit or the reception unit on the sheet. However, when an end of the sheet is open, an electromagnetic wave is reflected at the end of the sheet to generate a standing wave. As a result, when the size of a sheet is larger or nearly equal to the wavelength of the electromagnetic wave, intensity fluctuation occurs in electromagnetic field distribution on the sheet. Hence, Nonpatent Literature 2 discusses that the degree of electric coupling between the power transmission unit or the reception unit and a communication sheet depends on the position on the sheet.
In particular, when a standing wave distribution on the sheet corresponds to a voltage node, there is concern that the communication performance will greatly decline. Nonpatent Literature 2 also discusses a method of suppressing the generation of standing waves by disposing a resistor at the end of the sheet. In the case of this method, however, the resistor consumes power as heat, and hence reduction in communication performance cannot be prevented.